This application claims the benefit of Korean Application No. P2001-28521, filed on May 23, 2001, which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field of the Invention
The present invention relates to a portable information terminal having a liquid crystal display, and more particularly to a portable information terminal having a liquid crystal display fabricated according to a simplified module process and that is adaptive to small information devices.
2. Description of the Related Art
The mobile communications industry has witnessed a rapid expansion in the use of mobile communication terminals such as mobile phones, personal communication systems (PCS), etc. The study of hand-handled personal computer (HPC) or portable digital apparatus (PDA) with increased functionality compared to previous mobile communication terminals is also being actively pursued. Due to the development of information transmission techniques, motion picture information (e.g., IMT-2000) may be used to view moving images in real time.
A small portable information terminal uses a liquid crystal display LCD module as means of displaying a picture.
Referring to FIGS. 1 and 2, conventional LCD modules include a liquid crystal panel 11, a gate driving printed circuit board (PCB) 26, a data driving PCB 28, a gate tape carrier package (TCP) 18 and a data TCP 20 installed between the liquid crystal panel 11 and the gate and data driving PCBs 26 and 28, respectively, a gate pad 14 connecting the gate TCP 18 to gate lines GL, a data pad 16 connecting the data TCP 20 to data lines DL, gate driving integrated circuit ICs 22 and data driving IC""s 24 mounted on the TCP""s, and a connector 32 and a flexible printed circuit (FPC) film 30 for input/output wiring that connect a main board 34 to the gate and data driving PCB 26 and 28.
In the liquid crystal panel 11, liquid crystal cells are arranged in a matrix pattern at a pixel area between the crossing of the gate lines GL and the data lines DL (FIG. 2). A lower substrate 12 and an upper substrate 10 are joined together, and then liquid crystal is injected between the upper and lower substrates 10 and 12, respectively, to complete the liquid crystal panel 11. A plurality of gate pads 14 are formed at the edge of one side of the lower substrate 12 of the liquid crystal panel 11, and a plurality of data pads 16 are formed at the edge of a lower end of the lower substrate 12 of the liquid crystal panel 11. The gate pad 14 supplies gate signals from the gate driving ICs 22 to the gate lines GL. The data pad 16 supplies data signals from the data driving ICs 24 to the data lines DL. The gate pad 14 and the data pad 16 are bonded to the gate and data TCPs 18 and 20 by an anisotropic conductive film (ACF).
Input/output pads of the gate and data TCPs 18 and 20 are formed in input/output portions of the polyimide base film such that the gate and data driving ICs 22 and 24 may be mounted on the polyimide base film. Accordingly, the output portions of the gate and data TCPs 18 and 20 are joined to the gate and the data pads 14 and 16 and the input portions of the gate and data TCP""s 18 and 20 are joined to gate and a data driving PCBs 26 and 28.
The gate driving ICs 22 respond to control signals from a timing controller (not shown) mounted on the gate driving PCB 26 and sequentially supply scanning signals (i.e., gate pulses) to the gate lines GL. The data driving ICs 24 supply red, green, and blue (RGB) data received from the data driving PCB 28 to the data lines DL.
The main board 34 includes a microprocessor, a graphic processing circuit, etc., and supplies video signals and control signals to the data driving PCB 28. The data driving PCB 28 is connected to the gate driving PCB 26 via the FPC film 29.
The FPC film 30 accommodates input/output wiring and includes signal wires to provide a signal transmission path between the LCD module and the main board 34. The connector 32 is installed at the end of the FPC film 30 and connects the FPC film 30 to a jack of the main board 34.
In accordance with the tendency of the miniaturization of the above described portable information terminal, LCD size continues to decrease. However, because gate and data driving ICs of the LCDs are located at the left and at the bottom end, respectively, of the liquid crystal panel, the relative size of the driving ICs and their corresponding structures (e.g., PCB, TCP, etc.) increases. Also, due to the installation of each PCB and TCP at the side and the bottom of the liquid crystal panel, the process of bonding each gate and data TCP becomes more difficult and the number of LCD fabricating processes as well as the number of parts increase. Accordingly, it becomes difficult to make a portable information terminal small in size, light in weight, and thin in thickness.
Accordingly, the present invention provides a portable information terminal having a liquid crystal display fabricated according to a simplified module process and that is adaptive to a small information devices that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. These and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In order to achieve these and other advantages of the invention, a portable information terminal using an LCD according to an embodiment of the present invention includes a gate pad connected to a plurality of gate lines in a liquid crystal panel and formed at the edge of the liquid crystal panel; and a data pad connected to a plurality of data lines of the liquid crystal panel and formed in the liquid crystal panel parallel to the gate pad.
The portable information terminal further includes a gate driving circuit for supplying scanning signals to the gate lines to drive the gate lines; a data driving circuit for supplying video data to the data lines to drive the data lines; and a flexible printed circuit film on which the gate driving circuit and the data driving circuit are both mounted and to which the gate pad and the data pad are connected.
In the portable information terminal of the present invention, a timing controller is mounted on the flexible printed circuit film supplies data and timing control signals required at the gate driving circuit and the data driving circuit.
The portable information terminal further includes a main board where circuits are mounted for supplying control signals and data to the flexible printed circuit film; and a connector installed at the end of the flexible printed circuit film and connected to a jack of the main board.
In the portable information, the gate pad and the data pad have substantially the same pitch and may be formed at either the bottom or side end of the liquid crystal panel.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.